Investigators in HIV-1 prevention research from Johns Hopkins University (JHU) and the National Center for AIDS Prevention and Control (NCAIDS), Beijing, China propose that an HIV Prevention Trials Network (HPTN) site be established in Beijing with trial sites in Xinjiang and Guangxi autonomous regions to conduct HPTN trials among intravenous drug users (IDU), their sexual partners, and HIV-infected pregnant women. The People's Republic of China (PRC) with over 1.2 billion people has had an exponential increase in HIV-1 infection in these two regions with at least 70 percent of HIV infection known to be in IDUs, of which 84 percent are men and 16 percent are women. According to HIV seroprevalence surveys conducted in 1999 by the NCAIDS, there are currently an estimated 400,000 HIV-infected people in China with the number expected to reach 10 million by 2010. Approximately 50 percent of IDUs are HIV-1-infected in Xinjiang region (subtype C/B') and 40 percent in Guangxi region (subtypes C and E). The seroincidence rate among seronegative IDUs in Guangxi region in 1998 was 12.1 percent. Approximately, 1.7 percent of pregnant women were HIV- infected in 9/99 in a seroprevalence survey conducted in several hospitals in Uromqi City, Xinjiang region. This project has 3 specific aims. (1) To establish an HPTN site in China for the purpose of evaluating promising HIV prevention interventions with an emphasis on biomedical interventions such as detergent for inactivation of needles, nevirapine prophylaxis, and/or microbicides among IDU populations and their sexual partners/infants. (2) To provide scientific expertise/leadership in the development/implementation of the HPTN research agenda. (3) To further develop the clinical trials infrastructure and enhance the expertise/skills of Chinese investigators, students and staff in order to strengthen the HIV prevention efforts in China. The clinical, data management, laboratory, and administrative expertise and resources necessary to screen, enroll, and retain high-risk subjects in HIV-1 intervention trials will be derived from the current facilities, personnel, and organizational structure of the existing JHU-NCAIDS research collaboration using the public health network system in China. The specified area of interest and capability of this proposal is initially confined to evaluating biomedical interventions in IDU populations and their sexual partners/infants. However, the JHU-NCAIDS collaboration does have expertise in the areas of vaccines and behavioral interventions and could potentially employ these interventions in IDUs or expand to other populations as the epidemic grows.